1. Field of the Invention
This invention relates to devices for suppressing high-frequency electric noise, more particularly, to a new and improved ferrite electric noise suppressing device.
2. Description of the Prior Art
Ferrite is widely used to prevent electronic data transmitting cables from either receiving or transmitting unwanted high-frequency noise. The ferrite is formed to fully encompass the data transmitting cable at particular locations to prevent the cable from acting as an antenna for the unwanted high-frequency noise.
To maximize electric noise suppression, the ferrite must fully encompass the circumference of the cable at each desired location. In the prior art, electric noise suppressors have been formed from two symmetrical ferrite members joined about a cable with tape or wire ties. As an improvement over these early designs, electric noise absorbers are combined with plastic casings which house the ferrite members. The prior art designs, such as U.S. Pat. No. 4,885,559 entitled "ELECTRIC NOISE ABSORBER", include various biasing fingers formed unitary as part of the plastic casing which urge the ferrite members into engagement about the transmitting cable. The prior art plastic casings are also formed with gripping fingers for securing the casings to the desired location along the length of the transmitting cable, and with inwardly projecting fingers formed as part of the casing for loosely holding the ferrite in the casing. The ferrite members are not formed to tightly engage the transmitting cable, and the casings must be relied upon for maintaining the noise suppressor at the desired location.
The biasing fingers, the gripping fingers and the projecting fingers of the prior art noise suppressor casings are formed unitary therewith and require complicated molds and manufacturing procedures to be formed. Other prior art designs have been introduced to overcome these difficulties in manufacturing the complicated casing structures, and such other designs have utilized a separately formed metal spring which is mounted in the plastic casings for biasing the ferrite members about the cable as, for example, U.S. Pat. No. 5,486,803 entitled "SIGNAL DISCRIMINATOR". These designs obviously result in additional manufacturing costs since manufacturing and preparation of the metal spring members are required along with the assembly effort of mounting the metal spring members into the casing.
It is an object of the subject invention to provide an electric noise suppressor having a plastic casing in combination with biasing means which is easily manufactured and assembled.